[OSM-dev] RFC: map call to return deleted elements

Stefan de Konink stefan at konink.de
Sat May 23 14:44:50 BST 2009


Matt Amos wrote:
> On Sat, May 23, 2009 at 1:00 AM, Frederik Ramm <frederik at remote.org> wrote:
>> SteveC wrote:
>>> The SQL and filtering to get all the nodes in a bbox, then see if they
>>>  were still actually within the bbox, sort, etc... was non-trivial.
>> The main difficulty at that time probably was the SQL to return the "latest
>> version only" of each object. Matt won't have that problem because even if
>> he wants to return deleted objects, he can ignore the history tables - we
>> have the deleted objects in the current tables as well. (Plus, you didn't
>> have people with a degree in aeronautics. And very few Germans.)
> 
> this is OK for the nodes, but we still need to look at the history
> tables for the way nodes since the deleted version of the way in
> current_way_nodes is empty (ditto for relations). at this point i'm
> simply fishing to find out if people think its a good feature. it may
> turn out that it is expensive to implement, in which case we'll have
> to try something else ;-)

Isn't the problem here actually the reuse of a node? For example it was 
moved. If show a deleted way it would still depend on the latest data, 
hence not the data when a change was made?


Stefan




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